package com.haixiaoke.saas.repository.util;

/**
 * 经纬度距离计算工具类
 *
 * @author qixi
 */
public class LocationUtils {
    // 地球赤道半径
    private static double EARTH_RADIUS = 6378.137;

    private static double rad(double d) {
        return d * Math.PI / 180.0;
    }

    /**
     *  经纬度获取距离，单位为米
     * @param   lat1, lng1, lat2, lng2
     * @return  double
     * @author qixi
     *  2023/4/23 11:49
     **/
    public static double getDistance(double lat1, double lng1, double lat2,
                                     double lng2) {
        double radLat1 = rad(lat1);
        double radLat2 = rad(lat2);
        double a = radLat1 - radLat2;
        double b = rad(lng1) - rad(lng2);
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2)
            + Math.cos(radLat1) * Math.cos(radLat2)
            * Math.pow(Math.sin(b / 2), 2)));
        s = s * EARTH_RADIUS;
        s = Math.round(s * 10000d) / 10000d;
        s = s * 1000;
        return s;
    }


    public static void main(String[] args) {
        //正佳 113.333604,23.137837
        //南站 113.331655,23.156404
        double distance = getDistance(23.156404, 113.331655,
                23.137465, 113.333506);
        System.out.println("距离" + distance + "米");
    }

}
